The present invention relates to a tire puncture sealant.
Conventionally, a tire puncture sealant for repairing a punctured tire, which is prepared by blending natural rubber latex with an emulsion of a tackifier resin and an antifreezing agent, has been widely used (see, for example, JP 2004-035867 A and JP 3210863 B).
The tire puncture sealant is in the form of a latex in which natural rubber particles and tackifier resin particles repel each other by ionic repulsion, and dispersed and suspended in an aqueous solution of the antifreezing agent.
An example of the tire puncture sealant of this type is one including a latex of natural rubber, an emulsion of a tackifier resin, and an antifreezing agent, in which the tackifier resin of the tackifier resin emulsion is an aromatic modified terpene resin, and with respect to a total A+B+C of a solid content A of the natural rubber latex, a solid content B of the tackifier resin emulsion, and a content C of the antifreezing agent which is 100 parts by weight, the solid content A of the natural rubber latex is in a range of from 30 to 60 parts by weight, the solid content B of the tackifier resin emulsion is in a range of from 10 to 30 parts by weight, and the content C of the antifreezing agent is in a range of from 20 to 50 parts by weight (see JP 2004-035867 A).
Tire puncture sealants using synthetic rubber latexes such as acrylonitrile-butadiene rubber (NBR) latex and styrene-butadiene rubber (SBR) latex, have also been proposed (see JP 2005-170973 A and JP 2001-62934 A).
In general, such tire puncture sealant is injected into a tire through an air-charging portion of the tire and air is charged to a predetermined tire pressure, after which the car is driven to travel to allow the tire puncture sealant to reach a puncture; and the compression and shearing forces the tire receives when it rotates and touches the ground cause rubber particles to agglomerate to seal the puncture.
Recently used tires may puncture usually once every several years, so the frequency of actual use of the sealant is extremely low. Therefore, it is important for a tire puncture sealant to have sufficient performance to allow the long-term storage inside a car as well as excellent sealing properties.